Quality, Understandability and Reliability of YouTube Videos on Skin Cancer Screening.

In 2008, a nationwide skin cancer screening (SCS) program was implemented in Germany. However, participation rates remain low. YouTube videos on SCS might educate eligible persons to undergo SCS. Until now, no scientific evaluation of the quality of videos available for German-speaking persons eligible for SCS has been performed. Here, we identified and evaluated videos on SCS provided on YouTube. YouTube was searched in May 2022 for German terms related to SCS. Two authors evaluated the videos of the first three pages that met the predefined eligibility criteria. The quality of the videos´ information was evaluated using DISCERN and the Global Quality Scale (GQS). The understandability and actionability were assessed with the Patient Education Materials Assessment Tool (PEMAT). The reliability was assessed with the Journal of American Medical Association (JAMA) score. Subgroup differences were identified by the Kruskal-Wallis test. Overall, 38 videos were included in the evaluation. Most videos were provided by health professionals (clinics and practices). The average scores (mean (SD)) for the individual tools were as follows: DISCERN 3.1/5 points (± 0.52), GQS 3.72/5 points (± 0.7), understandability 64,27% (± 13.53%), actionability 58.22% (± 15.18%), JAMA 37.17% (± 18.94%). These results indicate a mediocre to good understandability, a mediocre quality and actionability, and a low reliability. Videos that were assessed as useful were of significantly better quality. An improvement of freely available informational videos on SCS, especially with regard to the reliability criteria, is urgently needed.

Bone marrow-derived myeloid progenitors in the leptomeninges of adult mice.

Although the bone marrow contains most hematopoietic activity during adulthood, hematopoietic stem and progenitor cells can be recovered from various extramedullary sites. Cells with hematopoietic progenitor properties have even been reported in the adult brain under steady-state conditions, but their nature and localization remain insufficiently defined. Here, we describe a heterogeneous population of myeloid progenitors in the leptomeninges of adult C57BL/6 mice. This cell pool included common myeloid, granulocyte/macrophage, and megakaryocyte/erythrocyte progenitors. Accordingly, it gave rise to all major myelo-erythroid lineages in clonogenic culture assays. Brain-associated progenitors persisted after tissue perfusion and were partially inaccessible to intravenous antibodies, suggesting their localization behind continuous blood vessel endothelium such as the blood-arachnoid barrier. Flt3Cre lineage tracing and bone marrow transplantation showed that the precursors were derived from adult hematopoietic stem cells and were most likely continuously replaced via cell trafficking. Importantly, their occurrence was tied to the immunologic state of the central nervous system (CNS) and was diminished in the context of neuroinflammation and ischemic stroke. Our findings confirm the presence of myeloid progenitors at the meningeal border of the brain and lay the foundation to unravel their possible functions in CNS surveillance and local immune cell production.